ISTANBUL/ANKARA, July 16 (Reuters) - An attempted Turkish military coup appeared to crumble in the early hours of Saturday after crowds answered President Tayyip Erdogan's call to take to the streets to support him.

Erdogan, who had been holidaying on the southwest coast when the coup was launched by a faction in the armed forces, flew into Istanbul before dawn on Saturday and was shown on TV appearing among a crowd of supporters outside Ataturk Airport.

The uprising was an "act of treason," and those responsible would pay a heavy price, he later told reporters at a hastily arranged news conference. Arrests of officers were under way, and it would go higher up the ranks, culminating in the cleansing of the military, he said.

See images from Turkey:

20PHOTOS

Possible military coup in Turkey

See Gallery

Possible military coup in Turkey

People take cover near a bridge during an attempted coup in Istanbul, Turkey July 16, 2016. REUTERS/Yagiz Karahan

Turkish solders stay with weapons at Taksim square as people protest agaist the military coup in Istanbul on July 16, 2016.
Turkish military forces on July 16 opened fire on crowds gathered in Istanbul following a coup attempt, causing casualties, an AFP photographer said. The soldiers opened fire on grounds around the first bridge across the Bosphorus dividing Europe and Asia, said the photographer, who saw wounded people being taken to ambulances.
/ AFP / OZAN KOSE (Photo credit should read OZAN KOSE/AFP/Getty Images)

Turkish solders stay with weapons at Taksim square as people protest agaist the military coup in Istanbul on July 16, 2016.
Turkish military forces on July 16 opened fire on crowds gathered in Istanbul following a coup attempt, causing casualties, an AFP photographer said. The soldiers opened fire on grounds around the first bridge across the Bosphorus dividing Europe and Asia, said the photographer, who saw wounded people being taken to ambulances.
/ AFP / OZAN KOSE (Photo credit should read OZAN KOSE/AFP/Getty Images)

People demonstrate outside Ataturk international airport during an attempted coup in Istanbul, Turkey, July 16, 2016. REUTERS/Huseyin Aldemir TPX IMAGES OF THE DAY

ANKARA, TURKEY - JULY 16: People react against military coup attempt, at Kizilay square in Ankara, Turkey on July 16, 2016. (Photo by Abdulhamid Hosbas/Anadolu Agency/Getty Images)

A group of approximately 50 young citizens of Turkey hold their national flag and shout slogans in support for Turkish President Recep Tayip Erdogan and his government, in Sarajevo on early on July 16, 2016.
Turkish citizens, mostly students who reside in Bosnian capital, responded to Erdogan's call for citizens to get out on the streets and show support for Turkey's government during the military coup. / AFP / ELVIS BARUKCIC (Photo credit should read ELVIS BARUKCIC/AFP/Getty Images)

Turkish military block access to the Bosphorus bridge, which links the city's European and Asian sides, in Istanbul, Turkey, July 15, 2016. REUTERS/Stringer

Turkish security officers detain Turkish police officers (in black) on July 15, 2016 in Istanbul, during a security shutdown of the Bosphorus Bridge.
The Turkish military on July 15 said that it had assumed power over Turkey, in what the prime minister has termed an illegal act. 'The power in the country has been seized in its entirety,' said a military statement read on NTV television, without giving further details. The military's website was not immediately accessible.
/ AFP / Yasin AKGUL (Photo credit should read YASIN AKGUL/AFP/Getty Images)

ANKARA, TURKEY - JULY 15 : 'There is an uprising attempt from within the army,' says Turkish Prime Minister Binali Yildirim. 'Those who are doing this will be punished in the hardest way.' (Photo by Ahmet zgi/Anadolu Agency/Getty Images)

ISTANBUL, TURKEY - JULY 15: Turkish soldiers block Istanbul's Bosphorus Brigde on July 15, 2016 in Istanbul, Turkey. Istanbul's bridges across the Bosphorus, the strait separating the European and Asian sides of the city, have been closed to traffic. Reports have suggested that a group within Turkey's military have attempted to overthrow the government. Security forces have been called in as Turkey's Prime Minister Binali Yildirim denounced an 'illegal action' by a military 'group', with bridges closed in Istanbul and aircraft flying low over the capital of Ankara. (Photo by Gokhan Tan/Getty Images)

A Turkish soldier stands on guard on the side of the road on July 15, 2016 in Istanbul, during a security shutdown of the Bosphorus Bridge.
The Turkish military on July 15 said that it had assumed power over Turkey, in what the prime minister has termed an illegal act. 'The power in the country has been seized in its entirety,' said a military statement read on NTV television, without giving further details. The military's website was not immediately accessible.
/ AFP / Yasin AKGUL (Photo credit should read YASIN AKGUL/AFP/Getty Images)

Turkish security officers detain Turkish police officers (in black) on July 15, 2016 in Istanbul, during a security shutdown of the Bosphorus Bridge.
The Turkish military on July 15 said that it had assumed power over Turkey, in what the prime minister has termed an illegal act. 'The power in the country has been seized in its entirety,' said a military statement read on NTV television, without giving further details. The military's website was not immediately accessible.
/ AFP / BULENT KILIC (Photo credit should read BULENT KILIC/AFP/Getty Images)

ANKARA, TURKEY - JULY 15 : 'There is an uprising attempt from within the army,' says Turkish Prime Minister Binali Yildirim. 'Those who are doing this will be punished in the hardest way.' (Photo by Ahmet zgi/Anadolu Agency/Getty Images)

ANKARA, TURKEY - JULY 15 : 'There is an uprising attempt from within the army,' says Turkish Prime Minister Binali Yildirim. 'Those who are doing this will be punished in the hardest way.' (Photo by Ahmet zgi/Anadolu Agency/Getty Images)

ANKARA, TURKEY - JULY 15 : 'There is an uprising attempt from within the army,' says Turkish Prime Minister Binali Yildirim. 'Those who are doing this will be punished in the hardest way.' (Photo by Ahmet zgi/Anadolu Agency/Getty Images)

Police officers stand guard near the Turkish military headquarters in Ankara, Turkey, July 15, 2016. REUTERS/Tumay Berkin TPX IMAGES OF THE DAY

Turkish military block access to the Bosphorus bridge, which links the city's European and Asian sides, in Istanbul, Turkey, July 15, 2016. REUTERS/Stringer

An injured man is carried near a bridge during an attempted coup in Istanbul, Turkey July 16, 2016. REUTERS/Yagiz Karahan

A group within Turkey's military has attempted to overthrow the government, Prime Minister Binali Yildirim said as security forces closed bridges along the Bosphorus and descended on Ankara and Istanbul.

A group within Turkey's military has attempted to overthrow the government, Prime Minister Binali Yildirim said as security forces closed bridges along the Bosphorus and descended on Ankara and Istanbul.

Up Next

See Gallery

Discover More Like This

HIDE CAPTION

SHOW CAPTION

of

SEE ALL

BACK TO SLIDE

Soldiers took control of the airport soon after Erdogan had landed, Reuters witnesses said. A senior official later said the soldiers were loyal to the government.

Rebel soldiers who had taken control of military aircraft were still firing from the air early on Saturday and fighter jets had been scrambled to intercept them, Prime Minister Binali Yildirim said, underscoring the chaotic situation.

Gunfire and explosions rocked both the main city Istanbul and capital Ankara in a chaotic night after soldiers took up positions in both cities and ordered state television to read out a statement declaring they had taken power.

A senior official said 60 people had been killed in the violence in Ankara alone, most of them civilians.

Early on Saturday, Reuters journalists saw around 30 pro-coup soldiers surrender their weapons after being surrounded by armed police in Istanbul's central Taksim square.

They were taken away in police vans as a fighter jet repeatedly screeched overhead at low altitude, causing a boom that shook surrounding buildings and shattered windows.

A successful overthrow of Erdogan, who has ruled Turkey since 2003, would have marked one of the biggest shifts in the Middle East in years, transforming one of the most important U.S. allies while war rages on its border. A failed coup attempt could still destabilize a pivotal country.

Before returning to Istanbul, Erdogan appeared in a video call to the studio of the Turkish sister channel of CNN, where an announcer held up a mobile phone to the camera to show him. He called on Turks to take to the streets to defend his government and said the coup plotters would pay a heavy price.

LAWMAKERS IN HIDING

By the early hours of Saturday, lawmakers were still hiding in shelters inside the parliament building in Ankara, which was being fired on by tanks. Smoke rose up from nearby, Reuters witnesses said. An opposition MP told Reuters parliament was hit three times and that people had been wounded.

A Turkish military commander said fighter jets had shot down a helicopter used by the coup plotters over Ankara. State-run Anadolu news agency said 17 police were killed at special forces headquarters there.

Momentum turned against the coup plotters as the night wore on. Crowds defied orders to stay indoors, gathering at major squares in Istanbul and Ankara, waving flags and chanting.

"We have a prime minister, we have a chief of command, we're not going to leave this country to degenerates"
Civilian

"We have a prime minister, we have a chief of command, we're not going to leave this country to degenerates," shouted one man, as groups of government supporters climbed onto a tank near Ataturk airport.

Erdogan and other officials blamed the attempted coup on followers of Fethullah Gulen, an influential cleric in self-imposed exile in the United States who once supported Erdogan but became a nemesis.

The pro-Gulen Alliance for Shared Values said it condemned any military intervention in domestic politics.

U.S. Secretary of State John Kerry said he phoned the Turkish foreign minister and emphasized "absolute support for Turkey's democratically elected, civilian government and democratic institutions."

The coup began with warplanes and helicopters roaring over Ankara and troops moving in to seal off the bridges over the Bosphorus Strait that links Europe and Asia in Istanbul.

Reuters reporters saw a helicopter open fire in Ankara. Anadolu said military helicopters had fired on the headquarters of the intelligence agency.

SOCIAL MEDIA CUT OFF

Airports were shut and access to internet social media sites was cut off in the first hours of the coup attempt.

Soldiers took control of TRT state television, which announced a countrywide curfew and martial law. An announcer read a statement on the orders of the military that accused the government of eroding the democratic and secular rule of law. Turkey would be run by a "peace council" that would ensure the safety of the population, the statement said.

TRT went off the air shortly afterwards. It resumed broadcasting in the early hours of Saturday.

Anadolu said the chief of Turkey's military staff was among people taken "hostage" in the capital Ankara but Prime Minister Yildirim later said he was back in control.

The coup had appeared strong early on Friday evening. A senior EU source monitoring the situation said: "It looks like a relatively well-orchestrated coup by a significant body of the military, not just a few colonels ... They control several strategic points in Istanbul."

One European diplomat was dining with the Turkish ambassador to a European capital when guests were interrupted by the pinging of urgent news on their mobile phones.

"This is clearly not some tinpot little coup. The Turkish ambassador was clearly shocked and is taking it very seriously," the diplomat told Reuters as the dinner party broke up. "However it looks in the morning, this will have massive implications for Turkey. This has not come out of nowhere."

Turkey, a NATO member with the second biggest military in the Western alliance, is one of the most important allies of the United States in the fight against the Islamic State militant group, which seized swaths of neighboring Iraq and Syria.

The Pentagon said there was no impact on operations against Islamic State from the U.S. air base at Incirlik in Turkey.

Turkey is also one of the main backers of opponents of Syrian President Bashar al-Assad in that country's civil war, host to 2.7 million Syrian refugees and launchpad last year for the biggest influx of migrants to Europe since World War Two.

Celebratory gunfire erupted in Syria's capital Damascus after the army claimed to have toppled Erdogan. People took to the streets to celebrate there and in other government-held cities.

Turkey has been at war with Kurdish separatists and has suffered numerous bombing and shooting attacks this year, including an attack two weeks ago by Islamists at Ataturk airport that killed more than 40 people.

After serving as prime minister from 2003, Erdogan was elected president in 2014 with plans to alter the constitution to give the previously ceremonial presidency far greater executive powers.

Turkey has enjoyed an economic boom during his time in office and has dramatically expanded its influence across the region. However, opponents say his rule has become increasingly authoritarian.

His AK Party, with roots in Islamism, has long had a strained relationship with the military and nationalists in a state that was founded on secularist principles after World War One. The military has a history of mounting coups to defend secularism, but has not seized power directly since 1980.